Multiple-spindle mixing kneader apparatus

ABSTRACT

A multiple-spindle mixing kneader, especially for carrying out thermal processes in liquid, pasty and solid phases, which is of the type comprising a stationary, generally horizontally disposed housing in the form of a drum member having a substantially centrally arranged stirrer shaft member upon which there are mounted radially extending members, typically discs or disc segments. Kneading bar members are arranged between the disc members or segments, also between the latter and the stirrer or agitator arms which move past the end walls of the housing, these kneader bar members wiping the inner surfaces of such housing. Further, a second stirrer shaft member is arranged parallel to the first stirrer shaft member in a further housing disposed parallel to the first housing. This second shaft member possesses stirrer arm members which, on the one hand, clean the inner surfaces of the aforementioned further housing and, on the other hand, also clean the shaft member and the lateral disc surfaces of the first stirrer shaft member. The invention specifically contemplates the provision of deflecting means for the material undergoing treatment in order to deflect such material from one cylindrical housing portion into the other, such deflecting means comprising deflecting discs mounted at the stirrer shaft members at a predetermined axial spacing from one another.

United States Patent List 1 .Sept. 5, 1972 [54] MULTIPLE-SPINDLE MIXING[57] ABSTRACT KNEADER APPARATUS A multiple-spindle mixing kneader,especially for car- [72] Inventor: Heinz List, St. Jakobstrasse 43,rying out thermal processes in liqui P and Solid Pratteln, Switzerlandphases, which is of the type comprising a stationary,

- I generally horizontally disposed housing in the form of [22] Flled'May 1971 a drum member having a substantially centrally ar- PP 144,048ranged stirrer shaft member upon which there are mounted radiallyextending members, typically discs [30] Foreign Application PriorityData or disc segments. Kneading bar members are arranged between thedisc members or segments, also between y 1970 Swltzerland "7660/70 thelatter and the stirrer or agitator arms which move past the end walls ofthe housing, these kneader bar ((5! "259/1123,1 members wiping the innerSurfaces of Such housing I! Further, a Second stirrer shaft member isarranged [58] Fleld 6 parallel to the first stirrer shaft member in afurther housing disposed parallel to the first housing. This secondshaft member possesses stirrer arm members [56] Reterences Clted which,on the one hand, clean the inner surfaces of UNITED STATES PATENTS theaforementioned further housing and, on the other hand, also clean theshaft member and the lateral disc surfaces of the first stirrer shaftmember. The invenv tion specifically contemplatesthe provision ofdeflecting means for the material undergoing treatment in PrimaryExaminer-Robert W. Jenkins Att0rney-Wemer W. Kleeman order to deflectsuch material from one cylindrical housing portion into the other, suchdeflecting means comprising deflecting discs mounted at the stirrershaft members at a predetermined axial spacing from one another.

5 Claims, 7 Drawing Figures mimmsrr 51912 1 3 3.689.035

rims" smz sum 2 0P3 MULTIPLE-SPINDLE MIXING KNEADER APPARATUSCROSS-REFERENCE TO RELATED CASE The instant development is animprovement upon the multiple-spindle mixing kneader disclosed in myco-pending United States application, Ser. No. 19,694, filed Mar. 16,1970, and entitled MULTIPLE SPIN- DLE MIXING DEVICE.

BACKGROUND OF THE INVENTION stirrer shaft member upon which there aremounted radially extending members, typically discs or disc segments.Kneading bar members are arranged between the disc members or segments,also between the latter and the stirrer or agitator arms which move pastthe end walls of the housing, these kneader bar members wiping the innersurfaces of such housing. Further, a second stirrer shaft member isarranged parallel to the first stirrer shaft member in a further housingdisposed parallel to the first housing. This second shaft memberpossesses stirrer arm members which, on the one hand, clean the innersurfaces of the aforementioned further housing and, on the other hand,also clean the shaft member and the lateral disc surfaces of the firststirrer shaft member.

In accordance with the development of this application there iscontemplated an improvement upon the above design of multiple-spindlemixing kneader, and specifically, this invention is manifested by theprovision of deflecting means for the material undergoing treatment todeflect such material from one cylindrical housing portion into theother, such deflecting means comprising deflecting discs mounted at apredetermined axial spacing from one another upon the stirrer shafts.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be betterunderstood and objects other than those set forth above, will becomeapparent when consideration is given to the following detaileddescription thereof. Such description makes reference to the annexeddrawings wherein:

FIG. 1 is a schematic front view of a mixing kneader designed forcontinuous operation;

FIG. 2 is a longitudinal sectional view through the mixing kneader shownin FIG. 1, taken substantially along the line I-l thereof;

FIG. 3 is a cross-sectional view of the mixing kneader depicted in FIG.2, taken substantially along the line II-II thereof;

FIG. 4 is a cross-sectional view of the mixing kneader depicted in FIG.2, taken substantially along the line III-III thereof;

FIG. 5 is a longitudinal sectional view of a mixing kneader, similar tothe showing of FIG. 2, and provided with intermediately arrangedfeedback conveying elements;

FIG. 6 is a longitudinal sectional view, similar to the showing of FIG.5, of a mixing kneader equipped with a second shaft which rotates andoscillates; and

FIG. 7 is a fragmentary detailed view through the outer peripheralregion of a specific construction of deflecting disc.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now thedrawings, in FIG. 1 there is shown in front view the construction ofmixing kneader apparatus according to one particular embodiment of thisinvention. More precisely, it will be understood that a substantiallystationary cylindrical housing 2 is supported by means of the braces orsupport elements 3 upon the base frame 1. The end faces of housing 2 areclosed by the flanged covers 4 and 5. At the end of the housing 2 whichconstitutes the drive side of the equipment there is flanged by means ofthe cage 6 the transmission 7 and drive motor 8 likewise supported uponthe base frame 1. At the opposite end of the housing 2 there is locatedthe bearing cage 9. The cages 6 and 9 are designed to possess asufiicient size that the packing sleeves, indicated at 60 and 9a, forthe stirrer shafts l3 and 19 can be easily serviced. The stirrer shaft13 is rotatably mounted in the main housing 2 whereas the other stirrershaft 19 is rotatably mounted in the auxiliary housing 50, similar tothe arrangement described in my aforementioned United States patentapplication. Further, the construction of the various members which aremounted at both stirrer shafts l3 and 19 may be similar to thatdisclosed in such application, and therefore, such will only beconsidered herein to the extent necessary to fully appreciate theunderlying concepts of this development, particularly since referencemay be had to this application for further details.

Now the product which is to be processed, with the embodiment underconsideration, is introduced into the infeed stud or pipe 10 and departsfrom the equipment at the outlet or outfeed stud ll. Apart from theseinfeed and outfeed studs there are also provided a number of furtherstuds 12 for withdrawing the vapors in the conventional manner. Also forthe purpose of preserving clarity in illustration there have beenomitted from the drawings a large number of the cleaning studs which aredistributed along the equipment.

The mode of operation of the equipment as well as that of the deflectingdiscs will be most readily understood by referring to thecross-sectional views depicted in FIGS. 2, 3 and 4. Upon the main shaft13 located within the main housing 2 there are mounted the end wallscrapers 14, the disc members or disc segments 15 provided with thethroughflow opening 16 and the deflecting discs 17. The kneading barmembers which are arranged between these elements have been designatedby reference character 18. Now on the other shaft member 19 which iswithin the housing 50 and parallel to the first mentioned primary ormain shaft 13 there are mounted the frame-shaped stirrer or agitatorarms 20 and the deflecting discs 21. Owing to the pitch or inclinationof the kneading bar members 18 and the axially parallel portion of thestirrer arms 20, and as described more fully in my aforementionedapplication, the product or material is conveyed from the inlet orinfeed stud towards the outfeed or outlet stud 11 and thereby iscontinuously mixed by means of the achieved stirring and kneadingeffect. In order to maintain the residence time span of the material atthe individual axial sections of the equipment narrower there areprovided at the main shaft 13 the deflecting discs 17 and upon theauxiliary shaft 19 the deflecting discs 21. The product arriving fromthe inlet stud 10 initially is conveyed towards the first deflectingdisc 17. This deflecting disc 17 either possesses no or only a verysmall throughpassage opening for the material in front of the associatedkneading bar members 18 so that this material is forced to deviate intothe second housing portion50 for the stirrer shaft 19. After thematerial is further processed therein at two additional axial mixingandkneading elements such material impacts against the deflecting disc 21.Also there the material does not find any or only a small throughpassage23 so that the material which has dammed up at the deflecting disc 21again is forced to deviate into the housing 2 of the main stirrer shaft13. This procedure of alternately deflecting the material from the mainhousing portion into the auxiliary housing portion and then back againinto the main housing portion and so forth repeats a number of timesuntil the product departs from the equipment through the agency of theoutlet stud 1 1.

Different arrangements are possible for the deflecting discs in order toachieve different effects. Thus as shown with the modification of FIG. 5there is provided an arrangement wherein, by reversing the angle at thekneading bar members 30 between the deflecting discs 17 and 21 it ispossible to achieve a partial feedback of the material and therefore animprovement of the mixing effect and the damming up.

FIG. 6 illustrates still a further embodiment of the multiple-spindlemixing kneader of this invention wherein the second shaft 40 equippedwith the stirrer blades or elements 41 both rotates and oscillates, thisbeing achieved through the provision of a suitable drive schematicallyindicated at reference character 100. The extent of the oscillatingmovement, represented by reference character 42, has been indicated bythe phantom line position of the deflecting disc 43 when it assumes itssecond axial terminal position. In this case the deflecting discs 43simultaneously serve to clean the lateral surfaces of the disc segments15, and thus they also tend to maintain themselves clean, in other wordsprovide a self-cleaning effect. In order to accommodate this short axialstroke it is advantageous to maintain the axial distance 45 between thedisc segments of the kneading elements and within which function thedeflecting discs 43, smaller than for the normal kneading elements.

The embodiments of the equipment shown in the drawings are preferablydesigned for continuous operation. However, the deflecting discs can bealso be utilized in conjunction with batch-wise operating mixingkneaders of the type disclosed in the aforementioned United Statesapplication.

In the case of mixing kneader equipment possessing considerable lengthit can be of advantage to employ the deflecting discs also forsupporting the shafts. Apart from the selection of suitable materialspossessing good dry running properties for the outside surface regionsof the deflecting discs, with this embodiment there is alsoadvantageously selected a special material for the contact locations ofthe associated housing, such as stellite, nitriding steel, and so forth,serving as the counter support. Similar to feed worms it is possible toimprove the bearing or support characteristics of the construction byproviding wedge-shaped grooves at the outer periphary of the deflectingdiscs or at the housing. Such construction has been shown, by way ofexample, in FIG. 7 wherein the lower portion of the housing has beenindicated by reference character 2 and within which travels thedeflecting disc 21. This deflecting disc 21 is provided at its externalperiphary with wedge-shaped grooves 44 which improve the bearing orsupport function of such discs. The arrow shown in FIG. 7 indicates thedirection of rotation, and by virtue of the wedge effect of the grooves44 the support characteristics for the deflecting discs 21 are thusimproved.

The mode of heating or cooling the heat transfer surfaces of theequipment is conventional and undertaken with the aid of standardmeasures which, here also, for the purpose of preserving clarity inillustration, and inasmuch as such does not constitute part of thesubject matter of this development, have been conveniently omitted fromthe drawing.

While there is shown and described present preferred embodiments of theinvention, it is to be distinctly understood that the invention is notlimited thereto but may be otherwise variously embodied and practicedwithin the scope of the following claims. Accordingly,

What is claimed is:

1. A multiple-spindle mixing kneader apparatus, especially for carryingout thermal processes upon materials in liquid, pasty and solid phases,comprising a first stationary housing having end walls, a first stirrershaft member mounted in said first housing, radially extending membersand stirrer arm means mounted upon said first stirrer shaft member,kneading bar members disposed between said radially extending membersand between said radially extending members and said stirrer ann meanswhich pass the end walls of said housing and serving to wipe the innersurfaces of said housing, a second housing mounted substantiallyparallel to the first-mentioned housing, a second stirrer shaft memberarranged substantially parallel to said first stirrer shaft member, saidsecond stirrer shaft member possessing stirrer arm means which clean theinner surfaces of said second housing and also said first stirrer shaftmember and the lateral surfaces of said radially extending members ofsaid first stirrer shaft member, means for deflecting the material fromone of the housings into the other housing, said deflecting meanscomprising deflecting discs mounted at a predetermined axial spacingfrom one another upon each of said stirrer shaft members.

2. A multiple-spindle mixing kneader apparatus as defined in claim 1,further including means providing wedge-shaped grooves at least at thedeflecting discs or the associated housing thereof to support theassociated shaft member.

3. A multiple-spindle mixing kneader apparatus as defined in claim 1,wherein said radially extending members are discs.

4. A multiple-spindle mixing kneader apparatus as defined in claim 1,wherein said radially extending members are disc segments.

5. A multiple-spindle mixing kneader apparatus as defined in claim 1,wherein said kneading bar members 5 exhibit a worm-like pitch in orderto achieve increased agitation and processing of the material.

1. A multiple-spindle mixing kneader apparatus, especially for carryingout thermal processes upon materials in liquid, pasty and solid phases,comprising a first stationary housing having end walls, a first stirrershaft member mounted in said first housing, radially extending membersand stirrer arm means mounted upon said first stirrer shaft member,kneading bar members disposed between said radially extending membersand between said radially extending members and said stirrer arm meanswhich pass the end walls of said housing and serving to wipe the innersurfaces of said housing, a second housing mounted substantiallyparallel to the first-mentioned housing, a second stirrer shaft memberarranged substantially parallel to said first stirrer shaft member, saidsecond stirrer shaft member possessing stirrer arm means which clean theinner surfaces of said second housing and also said first stirrer shaftmember and the lateral surfaces of said radially extending members ofsaid first stirrer shaft member, means for deflecting the material fromone of the housings into the other housing, said deflecting meanscomprising deflecting discs mounted at a predetermined axial spacingfrom one another upon each of said stirrer shaft members.
 2. Amultiple-spindle mixing kneader apparatus as defined in claim 1, furtherincluding means providing wedge-shaped grooves at least at thedeflecting discs or the associated housing thereof to support theassociated shaft member.
 3. A multiple-spindle mixing kneader apparatusas defined in claim 1, wherein said radially extending members arediscs.
 4. A multiple-spindle mixing kneader apparatus as defined inclaim 1, wherein said radially extending members are disc segments.
 5. Amultiple-spindle mixing kneader apparatus as defined in claim 1, whereinsaid kneading bar members exhibit a worm-like pitch in order to achieveincreased agitation and processing of the material.